Compressed gas is useful in a number of different applications. For example, compressed natural gas vehicles include a tank for storing compressed natural gas used for propulsion. The tank stores the gas at a high pressure for use by an engine of the vehicle. Currently, approaches used to compress gas from a low pressure source (e.g., a residential line) to a high pressure tank (e.g., a vehicle storage tank) include using direct mechanical compression. These direct mechanical compression approaches use a reciprocating piston movable within a cylinder to compress the gas. In use, these systems can be expensive as well as difficult to repair and/or maintain.